1. Field of the Invention
The present invention relates to lubricant compositions useful for preventing seizing of threaded fasteners. More particularly, the present invention relates to anti-seize lubricant compositions in non-flowable or solid form, which can be packaged in a convenient pocket-sized applicator dispenser.
2. Brief Description of Related Technology
U.S. Pat. No. 5,498,351 (Heffling) claims a process for making anti-seize lubricant compositions, and sets forth compositions of this type which include naphthenic oil, is lubricating grease, graphite, silicon fluid, and metal flake/oil suspension (65% aluminum flake and 35% oil). The compositions described are not in a solid form, but are generally formed as paste-like consistencies and are typically applied by dipping or brushing techniques.
Henkel Loctite Corporation has sold many flowable anti-seize lubricant compositions. For instance, C5-A Copper Anti-Seize is a suspension of copper and graphite in a high-quality grease, which protects metal parts from rust, corrosion, galling, and seizing at temperatures to 1800° F. (982° C.), and tested to MIL(PRF)-A-907-E; Nickel Anti-Seize is a copper-free product, recommended for stainless steel and other metal fittings to prevent corrosion, seizing, and galling in harsh, chemical environments, and temperatures to 2400° F. (1315° C.); Moly Paste is a low friction product, which lubricates press fits, protects during break-in and under high static loads up to 750° F. (400° C.); Silver Grade Anti-Seize is a temperature-resistant, petroleum-based inert lubricant compound fortified with graphite and metallic flake, which will not evaporate or harden in extreme cold or heat and is for use in assemblies up to 1600° F. (871° C.); Heavy Duty Anti-Seize is a metal free product, which provides excellent lubricity, outstanding lubrication to all metals including stainless steel, aluminum, and soft metals up to 2400° F. (1315° C.); Marine Grade Anti-Seize is formulated to protect assemblies exposed directly or indirectly to fresh and salt water; Marine Grade Anti-Seize works well in high humidity conditions, and has excellent lubricity, superior water wash-out and water spray resistance, and prevents galvanic corrosion, protects in temperatures from −29° C. to 1315° C. (−20° F. to 2400° F.); Graphite-50 Anti-Seize is an electrically conductive, non-metallic product, which is temperature resistant up to 900° F. (482° C.); Moly-50 Anti-Seize is a thread lubricant, which is temperature resistant to 750° F. (400° C.) and provides excellent lubricity; Zinc Anti-Seize protects aluminum and ferrous surfaces from seizure and corrosion up to 750° F. (400° C.); Food Grade Anti-Seize prevents seizure, galling, and friction in stainless steel and other metal parts up to 750° F. (400° C.); N-1000 High Purity Anti-Seize is a copper-based product, which is suitable for long-term, stainless steel applications and high-nickel, alloy bolting; N-5000 High Purity Anti-Seize is a nickel-based product, which lubricates and protects Class 1, 2 and 3 power plant hardware and is recommended for highly corrosive environments to 2400° F. (1315° C.); High Performance N-5000 High Purity Anti-Seize is also a nickel-based product, which provides maximum lubricating and anti-seize properties for Class 1, 2 and 3 power plant hardware. Temperature resistant to 2400° F. (1315° C.); N-7000 High Purity Anti-Seize is a metal-free product which provides high levels of purity and excellent lubricating properties for Class 1, 2 and 3 power plant hardware; and White Hi-Temp Anti-Seize is a non-metallic product which protects against high temperature seizing and galling of mated metal parts, up to 2000° F. (1093° C.), while demonstrating excellent lubricity and use on various metals, such as copper, brass, cast iron, steel and all alloys including stainless steel.
Recently it has become popular to place or to formulate certain adhesives, sealants, coatings and related products in a solid, stick-like form for easy transport and ready application by the end user. Examples of such products include “Semi-Solid Compositions for Removing Cured Product” (such as is described in International Patent Publication No. WO 01/92430), “Semi-Solid One- or Two-Part Compositions” (such as is described in International Patent Publication No. WO 01/92434), “Semi-Solid Primer Compositions” (such as is described in International Patent Publication No. WO 01/92435), “Spreadable Adhesive Compositions and Applicators for Use Therewith” (such as is described in International Patent Publication No. WO 01/91915) and “Polymerizable Compositions in Non-Flowable Forms” (such as is described in International Patent Publication No. WO 00/25628). All of these examples of solid adhesives, sealants and coatings and related products in a solid or semi-solid form are intended to be dispensed from a lipstick-type dispenser in which a mechanism at the base of the dispenser advances the solid or semi-solid product through an opening at the opposite end of the dispenser.
International Patent Publication No. WO 00/44528 describes a solid anti-galling agent that includes an anti-seize agent, hard waxes of long chain esters and alcohols having free carboxylic acid groups, such as candelilla or carnauba vegetable waxes, a moderate to high viscosity petroleum oil of 500 to 6,000 SUS, and surfactant, such as propoxylated myristyl alcohol or dodecylbenzene sulfonic acid. The surfactant is included at about 15 to 25% and is apparently required to maintain the homogeneity of the components and to soften and/or wet the hard waxes used therein. Such formulations are believed to be commercial products of LA-CO Industries, Inc., Elk Grove Village, Ill., which markets an E-Z Break Twist-Stick, Copper Grade, anti-seize formulation.
Other commercial anti-seize formulations in semi-solid form are available. For example, AS-201 Stick is a semi-solid anti-seize formulation offered by Dyna Systems, Dallas, Tex. This product is offered in a twist-up holder, but is a relatively soft semi-solid which retards retractability back into the container. Furthermore, the product is described as having storage and handling limitation of less than about 120° F. Kar Products of Des Plaines, Ill., markets a Kar Anti-Seize Stick. The stick is made from aluminum complex grease, paraffin wax, microcrystalline wax, aluminum powder and copper powder. The stick is a hard wax-based formulation, which is not typically amenable to good spreadability over substrate surfaces. Hard waxes also tend to crumble or crack, which also causes poor spreadability.
There is a need for an anti-seize composition in solid form having sufficient spreadability to evenly coat substrate surfaces while having dimensional stability to be stored and retractably dispensed from a container. More particularly, there is a need in the art for a non-flowable anti-seize formulation having dimensional stability up to and exceeding 120° F. so that it may be used in a variety of industrial settings.